Tornadogenesis
by Aki and Tenshi
Summary: Meteorologist AU! In which Sherlock is a genius forecaster, and John is an adrenaline-junkie expert storm-chaser. When they meet, chaos inevitably ensues.   Written for a kinkmeme prompt.   by Tenshi!
1. 01

**Warnings/Caveats:**

Characters in peril, vague implications of PTSD and depression that really don't show up very clearly in the text, a bit of language, purposeful and accidental Americanisms.

This fic deals with natural disasters in a way that, depending on your opinion of storm chasers, may be construed as flippant and disrespectful. Tornadoes and severe weather have been a real problem in America this year, with over 500 deaths already. **If anyone feels that this might be triggering or upsetting for you, please don't force yourself to read this!** I understand. I used to have a deep, obsessive fear about severe weather. The me of only a few years ago would not have been able to read this story, let alone write it! This fic is kind of a celebration for me, of the fact that I can hear the word 'tornado' now without having a crippling panic attack.

I tried to make sure all place names in the fic were made up, and to avoid too many references to historical tornadoes in order to not make light of any real situations or trigger any readers that may have been affected by severe storms in the past.

**Caveats:**

This fic has been proofread but not betaed. Any glaring mistakes are mine alone.

Also, I am nowhere near an expert in either meteorology or storm-chasing. I have taken some classes and done some research on my own, but there may be huge scientific errors peppered throughout the fic. I hope not! But if anything bothers you too much, please let me know :)

I am from the East Coast. I have never been further west than Tennessee. Therefore, any readers from the Great Plains area might find my depiction of their home states inaccurate and a little stereotyped. Once again, I hope not! Again, if there are any hilarious geographical mistakes, feel free to point them out so I can fix them!

**For more story notes, visit my LJ post. Link to my Livejournal is on my profile : )**

* * *

><p>There are days in spring and summer when the clouds grow to impossible heights and rake the sky. Hail pours to the ground and strikes with the force and sound of bullets. Wind shrieks through city streets like a hungry spirit.<p>

And sometimes, on particularly dark days, the clouds reach down to earth like the finger of God, twisting metal like paper, scouring the roads, and flinging debris like shrapnel.

These are the days when nature wages war against humanity.

John always likes to think of himself as the first line of defense, tracking down the enemy and calling in the reports himself.

Others monitor the battle from banks of computers, radar scanning the sky for every variable imaginable. John prefers to be out in the heart of the storm, to feel the wind pulling him and hear the roar of the vortex.

He likes to stare death in the face and smile.

It's the only time he feels truly alive.

* * *

><p>John's last chase before Sherlock Holmes ends in Helm, Nebraska when the car he's in hits another at an intersection at forty miles per hour.<p>

It's a miracle anyone survives, and leaves John with an aching knee and shoulder that's never quite the same. Harry flies in from London and begs him to come home with her. John doesn't think being in the middle of her and Clara's rows will be very good for his recovery and declines.

He and Bill Murray, his chasing partner, make a sorry sight in hospital, bloodied and bruised and probably about to be sued within an inch of their lives.

"There were _children_ in the car, Bill. I could've killed them."

"It wasn't your fault," Bill says for the eightieth time. "_I_ was driving; _I_ should've been more careful."

No matter how much Bill wants to take responsibility for the accident, John can never make himself believe it. Not when he can hear the echo of himself shouting "Sod the bloody stop sign; there's no one coming!" every night in his dreams.

Suddenly the storms don't feel like the only enemy out there.

It's almost two years before he chases again.

* * *

><p>Sherlock Holmes does not look like a storm chaser. He's far too well-dressed, sporting a slim-cut black suit over a crisp white shirt. He's tall and pale and something about his bearing screams 'money!' The man's probably never worn a T-shirt and jeans in his life.<p>

John can't help but wonder if he's just a thrill-seeker who doesn't know what he's getting into, but Mike has assured him that Holmes is an expert. Sure enough, barely five minutes after introducing himself John is being babbled at about CAPE values and wind shear and instability. He can only blink as Holmes outlines every place he expects a tornado to occur in the next two months. Mike swivels a bit in his office chair and grins at the expression on John's face.

"Hold on-" John breaks in when the man pauses to take a breath. "You _can't_ know all that. The weather forecast can barely tell me if it's going to rain tomorrow."

Holmes just sniffs. "Regardless," he says in that posh accent, the likes of which John hasn't heard since he left London. "This is what's going to happen." He pauses. "More or less. There's always something." The young man unfolds himself from his perch on Mike's desk. "How do you feel about the violin?"

"Excuse me?"

"The violin. Well – classical music in general, I suppose. I like to listen to it on long trips. Helps me think. Also, I may require you to drive somewhat later or at earlier hours than you had expected. I think it's only fair to warn you if we're going to be spending days in an enclosed space together." His face twists into what John supposes is intended to be a smile. "I did hope to begin soon. Is next week too early for you?"

"I- what?"

"Mike assures me that you're in possession of a car and an American driving license, so there should be no trouble on that front. Now, with regards to money: I will, of course, finance anything-" Holmes is striding towards the door as he speaks.

John grits his teeth for a second. "Now, wait here – I haven't actually agreed to this yet."

Holmes gives him a sideways look as he turns the door handle. "Mike, do give him my contact details. _Doctor_ Watson, I hope we can make arrangements soon." He winks – honest to God _winks_ – and is gone.

John can do nothing but gape.

"Well? What'd you think?" Mike is smirking at him.

"I think he's a nutter."

Mike laughs and crosses his arms. "But?"

"Who says there's a 'but?"

"_But,_ you'll let him chase with you," Mike says. "You haven't been out in ages, John, from what Bill tells me. That's not the John Watson I knew."

"Yeah, well." He rubs his shoulder. "I'm not the John Watson you knew."

Mike leans back in his chair. "Sherlock _is_ willing to pay you, John. I know you've been having money trouble since you quit-"

"Oh? Did Bill tell you that, too?" There's a sharp note to the question he wishes he'd been able to hide.

"He's just worried about you," Mike shrugs. "Just think about it, all right?"

* * *

><p>Their first day chasing is a blue-sky bust. John wishes there had been something – a rainstorm, a particularly interesting cloud structure, a bolt from the blue, <em>anything<em> to get his new chase partner to shut up.

Sherlock is not happy to have his forecast (tornadic supercells in northeast Kansas) proved so spectacularly wrong. With nothing but a clear sky mocking them overhead, he turns his attention to John, who had not previously been aware that all of the negative parts of his life were apparently written all over his face (and the order of cards in his wallet, the way he checks his mobile, etc.)

The ride to northeastern Kansas from Oklahoma City is six hours of trying to explain to Sherlock that asking how long someone has been unemployed is kind of rude, and that no, just because America is generally thought of as a pretty informal place does not make it any less inappropriate a question to ask.

Sherlock Holmes, John learns, is eccentric, to say the least. He's still overdressed for sitting in a car with a wonky AC for hours on end. At least the jacket and crisp white shirt are gone, replaced by a short-sleeved button-down in an expensive-looking fabric. He's also clearly accustomed to getting what he wants, judging by the petulant reaction to the sunny skies and the way he commandeered John's laptop the instant he got in the car. The man has no brain to mouth filter whatsoever, blinking at John with pale eyes and telling thing after personal thing about himself. (John takes great pleasure in telling him "Actually _Harry_ is short for _Harriet._" fifteen minutes north of the Oklahoma border, and watching the man's obvious frustration with himself.) When John floats the idea of going back to Oklahoma City for the night, Sherlock insists that they stay overnight in Kansas because he's _sure_ that storms are going to start forming in western Iowa overnight.

They stop for dinner at a little Italian place in Atchison. and John tries to pry some personal information out of Sherlock over a pizza.

The other man refuses to eat, seemingly too busy absorbing weather forecasts on his phone and sketching out isobar maps on his napkin.

"I looked at your website," John says. "The Science of Forecasting?"

"Oh?" Sherlock looks up. "What did you think?"

"A bit over my head, actually. You really aren't writing for amateurs are you?" He twirls his fork a little. "Can you really predict all those things you claimed? I mean, forecasting... not really known for being an exact science, right?"

Sherlock makes a face. "It would be much more exact if people would simply learn how to properly _observe_."

"Yeah, but you weren't exactly spot on today, either," John points out through a mouthful of cheese and pepperoni.

"If the capping inversion had broken I _would _have been, as you say, _spot on_." The man draws a line on his napkin map with unnecessary force.

"Talking of forecasting," John says. "What is it you do, exactly, besides pay washed up storm chasers to drive you all over the Great Plains?"

"I consult with various research departments at the NSSL when they're over their heads, which is always." Sherlock is bored with talking about himself now, eyes fixed again on his phone.

That night they stay in a hotel a little nicer than the ones he and Bill could afford. John burrows under the tacky floral duvet and dreams about a roiling black sky.

* * *

><p>John first experiences a tornado when he's ten.<p>

His mother drags the whole family to America to visit her brother on his fortieth birthday. Harry is bored with Oklahoma; she had planned to spend her holiday with friends, and there's not much to do in Uncle Tom's little rural community. John, however, is content kicking a football (_"Soccer_ ball," his uncle will laugh, flattening his vowels into a caricature of his wife's accent.) around in the neatly-trimmed grass. The yard is flat and sprawling, and it seems bigger than the park he plays in at home.

It storms several times. Sometimes they're rumbly spring squalls like John is used to, and sometimes he thinks 'storm' isn't a strong enough word for it – the wind screams around the house and hail pounds the roof like a monster trying to get in.

A few days before they're set to go home the tornado sirens go off. His uncle ushers everyone away from the dinner they'd just sat down to, and John spends the next thirty minutes in a bathtub with a pillow over his head. The eerie wailing is muffled this deep in the house, and is muted, eventually, by rain and wind fiercer than any John's ever heard in his life.

The twister's weak. Probably no more than an F0, John learns later. Most of the damage is a few streets away, though branches litter the yard and Aunt Liz's lawn flamingo is never seen again.

Harry is at once traumatized and bursting with eagerness to tell her friends about the tornado when she next sees them. Their father jokes that people will think the storm wiped out the whole state, the way she tells the story. He and his wife seem shaken, watching the skies uneasily afterwards.

It's the single greatest experience of John's life so far.

* * *

><p>The next day brings the storms Sherlock had predicted. He watches the radar maps on his laptop smugly as storm cells begin forming in east Nebraska in the early afternoon. By the time they move into western Iowa, he explains, the storms should have organized enough to produce hail and strong winds. Probably tornadoes, as well.<p>

The word brings John a sudden calm. He sips his hotel coffee and snaps the man's laptop closed with a steady handy. "Well then," he says. "Let's get on with it."

John drives them north on I-29 into Iowa. A traffic jam forms behind a car wreck, and John thinks Sherlock's going to jump out and begin pacing on the highway, he's so restless.

"The storms are already going tornado warned," Sherlock says, clicking impatiently on the computer balanced on his knees. He sighs loudly. "God, I need a cigarette."

"Not in my car, you don't," John says. Traffic inches forward.

Towering clouds have built to their northeast.

It's several minutes before police sort out the accident enough to start waving cars past.

"Finally," Sherlock says. "Take the next exit; we need to catch up with the middle cell." He turns the laptop so John can glance at it.

"Sounds good. You've got a map, right?"

"I've got a _computer_."

Sherlock leads them off the highway and out into farmland. The tornado-warned supercell he has his eye on hangs in the sky like a spaceship, a faint green glow signifying high water content in the massive clouds.

John turns on the radio and listens to the announcer warning citizens to take shelter immediately.

"Spotters reported a funnel cloud near Northumberland ten minutes ago." he says.

"I heard," Sherlock is terse, scanning the map in front of him. "Take the next right. That's not far from here."

John follows Sherlock's directions. They pass another storm chaser's car, made distinctive by the homemade weather station attached to the roof.

"Looks like we're on the right track," John says, speeding up a little.

"We're almost under the hook," Sherlock replies. "Keep an eye out to the east." He keeps his own gaze fixed out the window as they speed past a farmhouse, the surrounding trees bending as wind gusts around them.

"There! John, stop the car a moment!"

He hits the brakes and pulls them over to the side of the road.

"To your right, look!"

John squints in the direction indicated. They've approached the cell from behind, so the twister shouldn't be hidden behind rain. Sure enough, a thin funnel is reaching down from the clouds; it's low-contrast and far enough away to be difficult to see.

"Has it touched down yet?"

Sherlock produces a pair of binoculars from somewhere. "Yes, I can see the debris cloud. The condensation funnel is still transparent." He pulls the binoculars away from his face. "What are you waiting for? Get us closer!"

John wants to be miffed at the imperious tone, but his whole self has been seized by terrible, familiar focus. "Don't need to tell me twice," he says, and pulls them back onto the road.

Sherlock continues directing him through the country roads. John tries to keep one eye on the twister and one eye on the gawkers pulled over on the shoulder with their phone cameras pointed at the sky.

John's view is obstructed eventually, by trees lined up along a stream that cut under the road. The wind is shredding the leaves and sending them flying into the air.

"Another right, John!"

He pulls obediently onto a lane that appears to lead to a farmhouse off in the distance.

"It's just behind those trees. It should cross the road right in front of us."

John tears his eyes off the road and glances to his left. The stand of precisely planted trees is thrashing about ominously. "Are you insane?" he yells and throws the car into reverse. John stomps on the gas pedal and speeds backwards toward the main road. "We're too close!"

"We're fine!"

"_Jesus_ Christ," John says, slowing down as he feels they've reached a safe distance. "Are you trying to kill us?"

"There it is!"

One of the trees tips over, pulled up at the roots. It crashes to the ground dangerously near where John's car had been, and is quickly followed by a second tree and a electric pole. Wires spark as the tornado reaches the road.

"It's intensified," Sherlock calls over the roaring wind.

"I can see that!" John fumbles his mobile out of his pocket and turns on the camera, pointing it at the twister as it swirls out into empty pastureland. Leaves and twigs start to rain onto the car.

"Aren't you going to drive after it?"

"Not over downed power lines!" John clicks the camera off. "We can see it fine from here."

Sherlock is frowning when John glances over, but doesn't complain.

The tornado continues it's path through the fields, spinning up clouds of dust. It finally ropes out several minutes later, becoming smaller and smaller until it disappears.

John's fingers start to tremble a little on the steering wheel, and he laughs, adrenaline finally running out.

"That was the closest I've ever been to a tornado," he admits, starting to maneuver the car around to the correct position in the road.

"Really?"

"Yeah," he says. "Bill – the bloke I used to chase with – never liked getting too near. He was good at finding roads that kept us at a safe distance."

"Where's the fun in that?" Sherlock asks drily, looking at him out of the corner of his eye.

"That's what I always said!" John gives an undignified little giggle. He takes his gaze off the road for a moment to share a manic sort of grin with Sherlock. "So, Mr. Genius," he says. "This is what you do? Risk your life to prove you're a better forecaster than anyone else?"

"I hardly need to _prove_ anything."

"Idiot," John says, almost fondly. "So where to now? Try the cell to our south?"

"That one isn't going to produce anything of note. Back to the nearest town."

"Council Bluffs, I think. Check the map, won't you?"

"Looks about right. Do they have any good restaurants, do you know? I'm suddenly quite hungry..."

"I'm sure they've got somewhere good. You really shouldn't skip meals, you know. Oh, don't make that face at me; I'm a doctor!"

A sky peppered with puffy, smooth mammatus clouds looks down over their drive back west.

* * *

><p>A severe thunderstorm moves over their hotel that night. John stands out on the little balcony attached to his room and watches the lightning.<p>

Flashes of light are separated by seconds as streamers crawl through the clouds, occasionally stopping to strike the ground with a rumble or a deafening crack.

Somehow John isn't surprised when Sherlock appears behind him and steps out on the balcony, too.

"I don't recall them giving you a key to my room," John says without any real ire. Lightning crackles down and hits an antenna on a building barely half a mile away.

"You're not afraid of being struck," Sherlock comments mildly when the thunder stops.

John smiles up at the clouds, sticking his hand out to feel the rain. "Why would I be?"

Sherlock's mouth turns up on one side. "Why, indeed."

Above them, the storm continues into the night.


	2. 0102

Two days later, they intercept a small tornado outbreak across Oklahoma and North Texas. The real catch of the day is a picturesque white stovepipe tornado rambling through empty farmland a little after 5 pm. It's long-lived and far away from any towns, and for once John is content to simply lean against his car and watch it.

Sherlock seems a little miffed that he and John are not the only chasers who found the twister. Several cars are parked near theirs, and people have gathered at the edge of the road with cameras and tripods and other instruments.

He's even more miffed when a white SUV pulls up next to them and the driver hops out, wind tugging at his clothes.

"Sherlock Holmes!" he calls. He's older than John, tall and greying. His expression could be called friendly were it not for a distinct air of apprehension. "Didn't know you were in the country."

"Apparently, I am," Sherlock says, glaring over at the SUV. "I see Anderson managed to blunder his way into a correct forecast, for once. Unless you've finally recruited someone competent?"

"Oh, don't start," the man rolls his eyes. A young woman has climbed out of the SUV and is setting up a video camera on a tripod. Another man – Anderson, presumably - follows her out of the car.

Sherlock glances at John. "This is my _friend_, John Watson."

"Finally found someone willing to chase with you?" He sticks out his hand. "Detective Greg Lestrade, nice to meet you."

"Likewise," John shakes his hand. "You're a policeman?"

"Yep. Well- retired, now."

"Lestrade used to take me out chasing," Sherlock says.

"A _long_ time ago," Lestrade adds. "It was good seeing you again, Sherlock. You should come over for dinner, sometime. The wife would love to show you the new project she's working on." He raises an arm as though he's about to clap Sherlock on the shoulder, but thinks better of it. The man ambles back to his own team, where Anderson is taking a reading on a handheld anemometer.

"You never mentioned you've chased before," John says.

Sherlock shrugs. "A few times, years ago."

"Oh. What did he mean, _willing _to -"

"Look at the inflow tail, John!" Sherlock interrupts loudly. "Unusually long, wouldn't you say?"

John takes the hint and shuts up.

He does find out what Lestrade meant a bit later, after the tornado finally dies and the people watching on the roadside begin to pack up and peel off.

The young woman on Lestrade's team takes her time putting away her camera, and wanders over to where John is standing by the car.

"Sally Donovan," she says. "You're – Sherlock Holmes' new... colleague?"

"Yes," John says, cautiously.

"What? Did he hijack your car and make you bring him all the way out here?" She snorts. "He must be paying you. No one in their right mind would drive out into a storm with that man."

John can only frown at her. "What do you mean by that?"

"He's a freak," she says plainly. "He almost got us killed. _Three times_. The man's a psycho, and he has absolutely _no_ concern for anyone's safety." She closes the tripod with a snap. "People are already wary enough about chasers without Sherlock Holmes being out on the roads, making us all look bad." Sally shakes her head. "I'd drive him straight back to where he came from, if I were you."

John rubs his knee and tries not to think about the things people said to him after the accident. "Yeah, well. We're doing just fine, thanks."

"Suit yourself," Sally shrugs and heads back to the SUV, where Lestrade is gesturing for her from the driver's seat.

"Had a nice chat?" Sherlock appears behind John's shoulder.

"God!" he jumps. "Make a little noise, next time!"

Sherlock just raises his eyebrows at him.

"Come on, let's go find somewhere to eat," John unlocks the car and throws himself in. "And you can tell me where you think we should go next."

* * *

><p>Sherlock predicts more tornadic supercells in Kansas, so they spend the night in Dodge City. John spends half the evening in Sherlock's hotel room, trying to get his laptop back. The other man insists that yes, it is <em>absolutely necessary<em>, John, for him to look at both screens at once.

He leaves the room to get a Coke from the vending machine and nearly walks into a laptop when he comes back. Sherlock had apparently decided to stand in the doorway, waiting for him, holding up the computer at head height. He's quivering with excitement.

"Look at this, John!"

He does, sipping at his Coke. The radar map shows the area of Kansas they're in; a storm cell hovers ominously over an area to their south. A hook has started to form on the southeastern quadrant.

"No," John says.

"What?"

"No, I am not going on a night chase, Sherlock," he shoulders past him and picks up his own laptop off of the bed. "It's a good way to get us both killed."

"_John-_" Sherlock reaches out as though to stop him, hand brushing his side.

"_No,_" John takes the laptop back to his room. When he goes to plug it in, he realizes that the power cord is missing, probably still with Sherlock.

John's power cord is in Sherlock's room, but Sherlock isn't.

"Where the hell-?" With a sinking feeling, John pats his pocket, hoping to find his car keys still there.

They aren't.

"You bloody great-" John doesn't bother locking the room behind as he runs out. It hardly matters if someone steals Sherlock's things if he's too dead to worry about them.

Sherlock is waiting in the passenger seat when John reaches the car. He's twirling the keychain around on a finger when John opens the door.

"Give them back. Now."

Sherlock's hand closes around the keys. The hotel sign lights his faces up red.

"You know what the most dangerous thing about nighttime tornadoes is?" he remarks.

"You can't see them coming," John says, making a grab. Sherlock pulls his hand back. "Which is _why_ we're not going going out to chase one after dark, Sherlock. Now, give me back my keys, and get inside!"

"People in it's path," Sherlock says mildly. "Can't see it coming, either." He opens his fingers and drops the keys into John's palm. "They tend to be more deadly, as people often do not have enough warning to get to shelter in time." He buckles his seatbelt. "That seems like something you'd care about, _Doctor_ Watson."

John can only stare down at him. "Damn it."

He gets in the car.

* * *

><p>There's a wedge tornado bearing down on Scarlet, Kansas. They only have occasional glimpses of it, silhouetted by flashes of lightning.<p>

Sherlock is paying attention to the road for him as John phones it in.

"Yes," he's saying, "A large tornado, wedge. Maybe a quarter mile wide. It looks, God - F3 or F4. "

"F4," Sherlock murmurs beside him.

"We're on Lauriston Road, heading east. It's going towards Scarlet. They need to activate the sirens, _now_." He hangs up with the promise to keep them informed.

"Hook echo very well defined," Sherlock says, checking his laptop. "Might be getting stronger."

"God, I hope it misses the town."

Sherlock hums in response as John speeds up a little.

They have the radio going, a weather broadcast telling listeners that a violent tornado has been reported in the area.

"Seek shelter now, I repeat – Go underground or to an interior room in your house," the voice blares in the background.

"Don't regret the chase now?" Sherlock says, turning the volume down.

"Shut up," John says, without heat.

"There's a fork up ahead," Sherlock has his finger on the laptop screen. "The north route takes us close to the tornado."

"And the other?" John keeps both hands steady on the wheel.

Sherlock grins at him, face lit suddenly by lightning. "Who cares about the other route?"

John smiles back and hits the gas.

* * *

><p>Two people are killed by the Scarlet F4 when their mobile home is flipped over while they sleep. There are no other fatalities; the twister only clipped the edge of the town.<p>

The townsfolk attribute the lack of casualties the generous warning they had.

John watches the news reports and feels like he's woken up after a long sleep.

* * *

><p>A week later John finds Sherlock in one of the meteorology labs at OU. A few students hover outside the door, obviously unwilling to enter as long as Sherlock's in there.<p>

"You left your binoculars in my car," John says by way of greeting, plopping himself in a swivel chair.

"Thanks," Sherlock says distractedly. "Still on for next week, then?"

"Yeah."

"Good."

They sit in silence for a moment.

"You know," Sherlock says. "I'm thinking of relocating to Florida in a few months."

"Oh?"

"Yes. An acquaintance of mine has a flat she's renting out..."

"Oh." John says again, uselessly. "Isn't your job here?"

"Hurricane season is starting, John." Sherlock looks up and gives him a lopsided smile. "My _job_ is where the weather is. Besides," He stands and stretches. "It's a two bedroom flat."

John gapes at him a bit as he sweeps out of the lab.

"That is, if you're interested," Sherlock tosses back, smirking. "Hurricanes, after all. Could be dangerous."

John grins and follows him. "Oh, _God_ yes."

* * *

><p>John has no intention of getting back into chasing when he runs into Mike Stamford in Oklahoma City.<p>

"Who'd want to chase with me?" he asks, rubbing his knee. There had been some very nasty things posted about and him and Bill on storm chasing forums. Chasers didn't like it when people damaged their reputation with irresponsibility.

Mike just laughs. "You know," he says. "You're the second person to say that to me today."


End file.
